The Hummingbird features a unique optimum speed rotor technology that significantly improves overall performance efficiency by adjusting the rotor system's revolutions per minute at different altitudes, gross weights and cruise speeds. The autonomous unmanned aircraft, measuring 35 feet long with a 36-foot rotor diameter, eventually will fly more than 140 knots with a ceiling of 25,000 to 30,000 ft. (high hover capability up to 15,000 ft.) for up to 20 hours. Operational A160Ts will be capable of persistent intelligence, surveillance and reconnaissance; target acquisition; direct action; communication relay and precision re-supply missions.